Design And Implementation Of Embedded GUI And GIS System Based On Electronic Paper

Electronic paper (E-paper) display technologies have been relatively mature afteryears of development, which provides a technological base for the development of thenewly portable display devices. It has been applied to more and more fields because ofits good visibility, low power consumption and good portability. On the basis of theabove characteristics, the E-paper display is quite suitable for applications inembedded Geographical Information System (GIS). However, the problems existing inE-paper display, such as slow refresh rate, shadow problems after refreshment, havegreatly affected its growth and popularity.In accordance with the present problems of E-paper, this thesis starts withsoftware design, and implements a Graphical User Interface (GUI) which is speciallysuitable for E-paper display equipments. Moreover, based on the GUI, we design andrealize a GIS system with basic functions. In a word, the main work accomplished inthe present thesis includes the following three aspects:1) We study the display principle of E-paper, and make a comparison with theordinary electronic display devices. We also present a detailed analysis andexplanation related to the refreshment and display characteristics of E-paper.2) We analyze and compare some common GUI libraries, and combining withthe characteristics of E-paper, we design a GUI library used for E-paper and implementit in embedded Linux. The GUI firstly realizes the touch message response mechanismat the bottom, and provides the response interface for its up-applications; With respectto the refreshment characteristics of electronic paper, it provides a good refreshmentinterface; And it also encapsulates some common graphics, images and text processingmethods with eight grayscale display; Additionally, the GUI also provides some easilyprogramming components and calling interfaces for the users.3) Finally, based on this GUI, we design and implement an embedded GISsystem with the basic processing functions of geographic information. The GIS systemhas good properties of refreshment and display and common processing functions ofgeographic information, such as enlargement, reducing, roaming, normal query andlabel. We also propose a new optimization algorithm for maps cache for the GISsystem. The algorithm further improves the display speed of maps. The GUI library and embedded GIS system present in this paper have beenapplied in a practical project. The test results on PC analog and feedbacks from realapplications indicate that the GIS system can work steadily and efficiently, and reachesthe expected goals.